Steam-boiler furnace.



Patented Apr. 11, 1911. a sums-sum 1 azr . \M m x N m c an H nAl o .NN. v N n. xon H v w T D C Umm M mm m M SM n A 5 ow VN T. B. BU'IMAN. STEAM BOILER FURNACE.

APPLICATION TILED MAR. 14, 1908.

manned Apr. 11,1911.

6 SHEBTB SHEET 2.

T. R. BUTMAN. STEAM BOILER FURNACE.

APPLICATION I'LLED MAR. 14, 1908.

989,333. Patented Apr. 11, 1911.

5 EHEETS-SHEET 4:.

T. R. B TMAN. STEAM BOILER FUENAOE. APPLIOATION FILED MAR. 14, 1908.

Patented Apr. 11, 1911.

5 BHBBTS SHEET 6.

.III I THOMAS REED BUTMAN, OF LAKE BLUFF, ILLINOIS.

STEAM-BOILER FURNACE.

ceases.

Specification of Letters Patent.

Patented Apr. 11, 1911.

Application filed March 14, 1908. 1 Serial No. 421,028.

To all whom it may concern:

Be it known that I, THOMAS REED BUT- MAN, a citizen of the United States, residing at Lake Blufi', in the county of Lake and State of Illinois, have invented certain new and useful Improvements in Steam-Boiler Furnaces, of which the following is a specification.

My invention relates to improvements in steam boiler furnaces, and more particularly to furnaces for boilers of the vertical type.

Among the objects of my present invention are to provide means for the ignition of the coal by the direct impingement of a flame thereon, and in a novel manner to secure most perfect combustion of the coal and inflammable gases; to provide an improved rotating grate construction; to provide improved means for supplying air both above and below the grate; to provide improved means for feeding coal to the grate and im proved means for delivering ashes therefrom; and to provide a furnace structure of improved construction in general and in detail.

More particular objects of my invention will become apparent to those skilled in the art from the following description taken in conjunction with the accompanying drawings, wherein;

Figure 1 is a vertical section on line 1-1 of Fig. 2; Fig. 2 is a horizontal section generally 011 the line 22of Fig. l, but with parts broken away; Fig. 3 is a fragmentary section on line 33 of Fig. 2 with parts in elevation; Fig. 4: is an enlarged detail section on line 4=t of Fig. 3; Fig. 5 is a section on line 55 of Fig. 2 with parts in elevation. Fig. 6 is a section on line 66 of Fig. 2 with parts in elevation; Fig. 7 is an elevation of a suitable grate and oonveyeractuating mechanism, and; Fig. 8 is a View, part in section on the same general line as Fig. 2, showing a modified form of furnace embodying some of the features of my invention.

The preferred embodiment of my invention provides an annular rotating grate movable at relatively high speed and surrounding the lower drum of a vertical boiler, and I will describe my invention particularly as applied to such construction, but it will be apparent that in their broader aspects some of the salient features of my invention are not limited to such type of construction, and it will also become apparent that numerous changes and departures from the precise mechanical constructions herein illustratively shown may be made without departure from the spirit and scope of my invention.

In the drawings 10 indicates the lower drum of a vertical boiler, whereof 11-11 indicates vertical water tubes arranged in a circular space. The portion of the drum 10 within the combustion area is preferably protected by a tile fire wall 12 conveniently supported upon an I-beam collar 13 secured at a proper level to the drum. The outer wall is preferably cylindroconoidal in shape, and comprises a frame, sheathing and fire lining. The frame is composed of I- beams 14, arranged in vertical radial planes and bent to the desired shape. The exterior of the frame beams 14 is overlain by the cylindro-conoidal metal sheath, or shell. 15, and the frame beams are anchored against displacement by a circular footing 16 of angle iron at the floor level, a reinforcing band 17 at the knees or angles of the beams, and a channeled ring 18 at the top of the beam, receiving upper ends of the beams in its channel with the inner edges of the beams against its down-turned edge. At the grate level there is secured to the outer wall structure a dead plate 20, having at its inner ex tremity an annular gutter 21, arranged opposite to a corresponding inner dead plate 22 guttered as at 23 and interposed between the tile wall 12 and the annular I-beam 13.

The spaces between the frame beams 14: are preferably filled in with brick work 25, preferably extending flush with the inner surfaces of the I-beams throughout their entire extent, and the dead plate 20 affords support to a vertical lining or fire wall 26 spaced apart from the wall 25, to leave therebetween an air channel 27, closed at its bottom by the dead plate and at its top by a filling strip 28 at the level of the knees, said wall 26 supporting in turn the frusto-conoidal fire wall 29 tapering inward at an angle of about 30 to almost meet the tubes 11, and preferably spaced apart somewhat from and parallel to the casing wall 25.

30 indicates in general an annular grate of suitable construction, preferably providing a central perforated burning area 31, and annular imperforate, dead edges 32, provided with downturned lips or flanges 33, loosely fitting in the gutter 21 and 23 of dead plates 20 and 22 to make a sealing broken oint.

The grate may be constructed and braced in any suitable manner, it being my preference to employ a construction substantially conforming with my prior Patent No.

728,362 dated May 19, 1903, such construction, as herein shown providing inner and outer annular rims and 36 connected by radial stays 37 and suitably b need as with trusses 38, the outer rim 36 having bolted thereto an annular downwardly facing rack 39, whereby the grate may be driven in rotation.

For carrying the grate in rotation I preferably provide a series of radially disposed shafts a0, journaled in iimer bearings 41 secured to the I-beam 13 and in outer bearings 12, secured to the I-beams let, and acting as lower braces for the dead plate 20, such shafts carrying wheels 43 on which the rims 35 and 36 bear. For directing the grate in its proper circular path, a series of horizontal wheels 11, adjustably mounted beneath the (lead plate 20, may be provided and take the lateral thrust of the rack 39.

For feeding green coal to the active or perforate part of the grate, I provide upon the exterior of the conoidal portion of the casing a feed hopper 46 from which extends radially inward a tubular chute 17, at its lower end downturned as at 18, leading into a feed chamber 19 included between walls 30 and 51 traversing the grate, and overlain oy a slab 52, the wall 50 being formed of an iron seated in the inner and outer walls 12 and 26, and carrying a protecting slab and the wall 50 being preferably of iron only. The chute 4L8 terminates at a suitable distance above the grate level and is preferably provided with an exterior feed adjusting sleeve 53, vertically movable by means of a chain 54 running over pulleys 55 and connected to a non-rotatable nut 56 mounted on a rotatable screw 57 extending to and operable from the exterior of the casing, the nut 55 being held against rotation in any suitable manner, as by mounting in a square tube 56 as shown in Fig. 4. Preferably also to prevent tilting or dragging of the sleeve 53 a vertical angle iron brace 58 is secured within the vertical chute portion 52 at the rear side thereof with reference to the direction of rotation of the grate. A suitable door-opening to the chamber 419 is made through the casing as at 59.

It will be apparent that the depth of the fire may be regulated by vertical adjustment of the sleeve 53, the height of the front wall 50 above the grate also determining the maximum depth of the coal bed on the grate.

The grate is relieved from ashes or material lodged thereon, to prepare it for the reception of fresh coal, by the provision, im-

-mediately in rear of the feed chamber 49,

(directions throughout being taken with reference to the direction of travel of the grate, except where otherwise stated,) of a conveyer structure 60, preferably comprising a rotating worm, extending diagonally across the grate with a rearward inclination from its outer to its inner end and adapted to mill ashes therefrom to a delivery point preferably at the front of the casing.

In the specific construction shown 61 indicates a conveyer housing afiording support at opposite ends to a shaft 62 carrying a screw conveyer 63 which extends into close proximity to the grate, and serves to convey the ashes from the grate to an opening 6-1 leading through a suitable ash chute 65 to an open mouth 66 in the exterior casing.

The housing 61 for the conveyer worm 63 is arranged to leave a rear opening up to approximately the level shaft 62 and its front wall is provided with a pivoted scraper 68 which dips back under the conveyer and has its free edge riding over the traveling grate to prevent the escape of ashes past the conveyer. The conveyer housing is protected against burning out by a protection wall 69 of tile and angle iron, parallel to the wall 51 heretofore mentioned, the walls being bridged over by a refractory slab 70, as best shown in Fig. 6. As illustrated in Figs. 2 and 7, a common mechanism may be employed for driving the ash conveyer in rotation and rotating the grate, such mechanism comprising a power receiving pulley 71 on the conveyer shaft, and an eccentric 72 upon said shaft communicating motion through an eccentric strap and connecting rod 73 to a lever 74:, wherewith. the link 73 has slot and bolt connections for adjustment, the lever 74 being pivoted upon a stub-shaft 75, mounted on the furnace casing and carrying a ratchet 76 wherewith a pawl 77 on the lever 7 a engages, the ratchet 76 being fixedly connected to a pinion 78 which meshes with a gear 79, mounted upon a shaft 80 extending through the furnace casing and, as best shown in Fig. 3, bearing a pinion 81 which meshes with the annular rack 39 of the grate construction.

In conjunction with the furnace as described, I provide means for igniting the coal freshly deposited on the grate in a manner which I believe to be new, making provision for the direction of a comparatively intense blast of flame upon the exposed upper surface of the green coal, so that its top may be ignited and the fire caused to eat furnace proper a small Dutch oven furnace, generally indicated at 85, of suitable construction providing av combustion chamber 86 above a grate 87 to which fuel may be supplied to a fire door 88, and below the grate providing an ash pit 89 to which access is had through an ash door 90. These parts may be of any usual or preferred construction, the arrangement being such that the combustion chamber 86 opens through a low, wide throat 91, to the rotating grate of the main furnace at about the level that the coal will reach as fed from the supply chamber 4E9, and immediately in front of said chamber 49.

It will be obvious that a small fire maintained in the oven 85 will have its flame directed in blast across the surface of the freshly supplied coal as it emerges from the supply chamber 49, so that the top or upper surface of the-coal will be ignited as fast as it comes from the supply chamber, and the fire will burn downward through the coal as the coal progresses with the moving grate. The fuel consumed in the Dutch oven need be only small inquantity for the desired purposes, and in many installations the provision of such auxiliary furnace or oven is advantageous as providing a convenient refuse burner the heat of which may be utilized. In order to insure heating of the tubes of the boiler which stands in radial alinement with the dead space taken up by the fuel supply and ash removing devices, I throw diagonally across the combustion chamber from the upper front corner of the throat 91 to the top of the fire wall 11- a rearwardly-trending, laterally-inclined deflecting or baffle arch 9Q inclined upward from its rear to its front edge, and having its inner edge in rear of a radial line struck from its outer edge. This arrangement insures the deflection of a portion of the flame and hot gases issuing from the throat 91, into the tube area radially alining with the dead space of the grate overlain by the coal feeding and ash removing devices.

The arrangement above described, resulting in the top ignition of the freshly introduced coal, renders it highly desirable that air should be supplied above the grate level throughout the area where active distillation of the gases occurs, and I. have found it advantageous to introduce such air in a heated condition. To this end I utilize the annular air space 27 between the inner and outer sections of the furnace ,wall as an air heating passage, and, therefore, I provide an inlet 95 through the outer furnace wall to the channel 27, at a point in rear of the ash conveyor, regulating the opening with a sliding door 96, and through the inner lining 26 of the furnace wall, I provide small ports 97, opening slightly above the fire level and arranged in positions in numbers l and with outlet capacity approximately proportionate to the activity of distillation in the proximate areas of the grate. Thus it will be seen in Fig. 2 that the number and closeness of the ports 97 increase as they approach the point of introduction and ignition of the coal, the number of ports being greatest in the area confronting the portion of the grate a short distance ahead of the ignition oven. l urthermore, I preferably provide in the furnace for independent regulation of the air supply to the under side of the grate, in different sections thereof, where it may be desirable to vary the activity of the combustion. To this end I provide a series of radial walls 98, in suitable number, each such wall extending approximately radially from the drum 10 to the casing 15, and vertically from the floor level to the line of the grate rims 35, 36. Into each air supply section bounded by walls 98, an inlet opening 99 is made, regulable by a slide door 100.

It will be apparent to those skilled in the art that the top ignition of the coal in accordance with my invention, may be accomplished by constructions widely different from that heretofore described, and in Fig. 8 I have indicated one of the many various forms in which the invention might be embodied. In the furnace therein shown, it will be understood that the construction is otherwise similar to that heretofore described, save that the ignition oven is done away with and the channel 27 made to open to the combustion chamber only at a point 101 in front of the coal feeding devices, at a point where combustion may be active, at such points there being provided an injector arrangement 102, for directing a blast of steam and air across the ignited coal to direct the flame backward over the freshly introduced coal, thereby causing top ignition of the freshly introduced coal by a flame blast in a different manner than that disclosed in the remaining views.

In the operation of the furnace, it will be understood that the coal fed through the hopper and the proper spout is properly distributed practically uniformly over the active area of the grate surface to a height limited by the arrangement of the wall 50 (Fig. 6) and its top ignited by the blast of flame impinging thereon, and preferably generated by means extraneous to the furnace, as in the Dutch oven construction shown. Air is introduced to a regulated extent into each section of the air pit below the grate, leakage around the grate being minimized by the tongue and gutter joint which may be packed with ashes or the like, and the fire burns down through the mass of coal, so that the distilled gases arise through the burning coal and, admixed with heated air supplied through the ports 97, are burned within the furnace so enabling practically smokeless consumption of the fuel to be effected. As the grate is moved in rotation the burning mass of coal is carried around, the ignited coal mass being free from contact with the inner or outer fire walls of the combustion chamber, so that said walls remain practically free from clinkers, and in successive stages of its progress the air supplied to the coal is regulated so as to secure the desired rapidity of coal consumption. Usually, of course, the air supply apertures 99 are open to progressively greater extent in the direction of progress of the coal, the air supply is so calculated that the coal is about burned out and dead when the revolution of the grate is completed. I have found in practice, however, that even where through carelessness or otherwise live coal is permit-ted to come in the range of action of the ash conveyer, the machinery is not damaged, as such air as enters through the ash chute 66 tends to blow out under the back Wall 69 and carry away the heat. The ashes are removed from the grate by the comparatively rapid rotation of the conveyer 63, and are deposited outside of the furnace, such fine material as sifts down through the grate aperture being readily removable from the air chambers below through the openings 99.

Having thus described my invention what I claim and desire to secure by Letters Patent, is:-

l. The combination of a movable fuel support, a stationary fuel support, independent means for supplying fuel to said supports, the movable fuel support adapted to present continuously the green fuel upon the movable fuel support to the direct action of the flame from the fuel on the stationary support.

2. The combination of a rotating grate, a stationary grate adjacent the path of the rotating grate, independent means for supplying fuel to said grates, the rotating grate adapted to present continuously the green fuel thereupon to the action of the flame from the fuel on the stationary grate.

3. The combination of a rotating grate, a stationary grate adjacent the rotating grate, means for automatically feeding coal onto said rotating grate at a point in advance of the stationary grate, independent means for supplying coal to the stationary grate, and means for removing ashes from the rotating grate at a point in advance of the coal feeding means.

4. In a furnace, a rotary grate, means for feeding green coal thereto, an ignition apparatus adjacent one side of the feeding means for directing a flame over the green coal to ignite the top thereof, and means adjacent the other side of said feeding means for the removal of ashes.

5. In a furnace, the combination with a combustion chamber and a moving grate therein,- of a separate fuel burning ignition device provided with a separate combustion chamber, communicating with the first named combustion chamber, arranged to deliver its flame to coal on the moving grate.

6. In a furnace, the combination with a combustion chamber and a rotary grate therein, of automatic means for feeding coal thereto, an auxiliary furnace having a separate combustion chamber, separate means for feeding coal thereto, said combustion chambers communicating through a restricted passage directly above said grates and in front of the automatic coal feeding means.

7. In a vertical steam boiler furnace, the combination with the boiler having vertical water tubes, of a rotary grate encircling the boiler, means for supplying green coal to said grate, means for directing a blast of flame across the top of the coal freshly sup plied to the grate adjacent the coal feeding means, and means for directing a portion of said flame toward the water heating surfaces in radial alinement with the coal feeding means.

8. In a vertical steam boiler furnace, vertical surfaces to be heated arranged in a circular space, a rotary grate encircling said space, a coal feeding chamber bridging the grate and extending to the heating surface space, an ignition oven opening above the grate in frontof the feeding chamber, and a deflector wall spanning the grate inclined toward the coal chamber from its outer to its inner end and from its lower toward its upper edge.

9. In a furnace, an exterior shell, an annular rotating grate within said shell, a coal hopper outside of said shell, a tubular spout leading from said coal hopper to a point above the grate, a sleeve surrounding the lower extremity of said spout, a brace 58 and means extending to the exterior of the shell for vertically adjusting the sleeve.

10. In a furnace, a rotating grate, refractory walls forming a chamber about said grate, and a conveyer above the said grate within said chamber for removing ashes from the grate, and a housing partially surrounding said conveyer.

11. In a furnace, an endless rotary grate, a housing partially surrounding said conveyer and providing bearings therefor, and a screw conveyer extending across and above said grate in a line diagonal with respect to a radiusof said grate for removing ashes therefrom.

12. In afurnace, a rotary grate, a conveying device extending transversely across and above said grate at an angle to a line radial from the center of the furnace, comprising a casing, and a screw conveyer within said casing, there being an opening from the exterior end-portion of said conveyer casing directly to the atmosphere, said conveyer being in operative relation with said grate to remove ashes therefrom.

13. In a furnace, a rotary grate, a screw conveyer above the grate adapted and arranged to remove ashes therefrom, said conveyer extending transversely of said grate at an angle to a line radial from the axis thereof, a housing for said conveyer, having its rear side relative to the rotation of the grate, open, and its relatively front side at a substantial level with the grate inclined back toward the center of the screw.

14:. In a furnace, a rotating grate, a screw conveyer, traversing and arranged above the 15 grate, and a pivoted scraper carried by the 20 front side of said grate.

In testimony whereof I hereunto set my land in the presence of two witnesses.

THOMAS REED BUIMAN.

In the presence of- FoRfiE BAIN, MARY F. ALLEN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

